<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Operater</title>
</head>
<body>
	<script>
		var x = 5 + 5;
		document.write(x);
		document.write('<br>');

		var x = '5' + '5';
		document.write(x);
		document.write('<br>');

		var x = 5 + '5';
		document.write(x);
		document.write('<br>');

		var x = '5' + 5;
		document.write(x);
		document.write('<br>');
	</script>

	<h3>规则是：</h3>
	<p><strong>如果把数字与字符串相加，结果将成为字符串。</strong></p>
</body>
</html>